https://seclists.org/oss-sec/2025/q3/137: libssh2 Base64 Encoding Heap Overflow in Known Hosts SHA1 Hash Processing
Published Aug 26, 2025
·Updated
Affected Software
1 affected component
libssh2 libssh2
Frequently Asked Questions
1
What is the severity of CVE-2025-XXXX?
The severity of CVE-2025-XXXX is classified as critical due to its potential to cause remote code execution.
2
How do I fix CVE-2025-XXXX?
To fix CVE-2025-XXXX, update to the latest version of libssh2 that addresses the heap buffer overflow vulnerability.
3
What systems are affected by CVE-2025-XXXX?
CVE-2025-XXXX affects all versions of libssh2 that utilize the libssh2_knownhost_readline() API with malformed hashed hostname entries.
4
What are the potential impacts of CVE-2025-XXXX?
The potential impacts of CVE-2025-XXXX include unauthorized access and remote code execution on affected systems.
5
How does CVE-2025-XXXX exploit the heap buffer overflow?
CVE-2025-XXXX exploits the heap buffer overflow by processing specially crafted inputs that exceed the allocated buffer size during base64 encoding.